1. Field of the Invention
The present invention generally relates to housings, and particularly, to a housing used in electronic devices, and a surface treating method for making the housing.
2. Discussion of the Related Art
In recent years, there has been an increase in demand for portable electronic devices, such as personal digital assistants (PDAs), mobile phones, MP3 players and MP4 players. To make the portable electronic devices more physically appealing, the housings of the portable electronic devices may be decorated to have different appearances.
Generally, housings that exhibit different appearances are done by layers of coating. A typical method for making a housing having metallic appearances includes the following steps: first, coating a primer onto a surface of a plastic board to form a bottom layer; second, depositing a metallic layer on the bottom layer by vacuum metallization.
However, the metallic layer formed by vacuum metallization has relatively high chemical activity, thus metallic layer is prone to being oxidized or corroded. Thus, the appearance of the housing may be compromised.
To prevent the metallic layer from being oxidized or corroded, generally a transparent layer is coated on the metallic layer to form an outer layer. The outer layer may protect the metallic layer to a certain extent and for a certain time. However, the outer transparent layer would, eventually, peel off from the metallic layer, leaving the metallic layer exposed to oxidation or corrosion.
Therefore, a new housing and surface treating methods for making the housing are desired in order to overcome the above-described shortcomings.